15x8 rallys on 74 duster

I would like to put 15x8 rallys, with 4.5 backspace on the rear of my 74 duster. I have 15x7 w/4.125 backspace w/ 275/60/15 tires w/ 1/4" spacer so tires clear leaf springs now. I don't want to order the 15x8
wheels unless they will fit. I also have stock inner wheel wells.
I plan on installing a offset hanger kit if necessary. I just don't want to do the inner wells. Can anyone running the 15x8 rallys advise if they will fit?
Also what tire your running, and want to keep the car at stock height.